The invention relates to a light emitting diode (LED), and more particularly to a ZnX LED, where X is S, Se, Te or a combination thereof.
Light emitting diodes are used as display and lighting devices. Working principles comprise voltage applied to a diode to drive electron and hole combinations, releasing light from the diode. Luminescence characteristics, such as color and intensity, are based on energy gap and quantum efficiency of the luminescent materials.
A popular LED structure is shown in FIG. 1, in which LED 10 comprises a lead frame 11, a GaN LED chip 12 therein, and a packaging material 13 covering GaN LED chip 12. A plurality of YAG phosphors 14 are dispersed in packaging material 13. YAG phosphors 14 are synthesized at high temperature (>1000° C.), creating large particles.
YAG phosphors 14 also present poor dispersion due to incompatebility with packaging material 13, negatively affecting luminescent uniformity.
It is desirable to resolve these and other problems and obtain higher luminescent efficiency for the LED.